Compression and expansion machines for gaseous bodies



K. BECHTOLD June 17, 1958 COMPRESSION AND EXPANSION MACHINES FOR GASEOUS BODIES 3 Sheets-Sheet 1 Filed Feb. 28, 1956 June 17, 1958 K. BECHTOLD COMPRESSION AND EXPANSION MACHINES FOR GASEOUS BODIES 3 Sheets-Sheet 2 Filed Feb. 28, 1956 June 17, 1958 BECHTQLD 2,839,240

COMPRESSION AND EXPANSION MACHINES FOR GASEOUS BODIES Filed Feb. 28, 1956 I 5 Sheets-Sheet 3 E a r o o 2 839 2 l H 'fin 3, 1. :s r a i "I. l n i i be l fig fi'klfiil MQTMAUU gbwfiii: i Wily Patented June 17, 1958 pairs of slots L L and L lying on one diameter pairs of slides S S and S the lengths of which are equal to 2,839,240 the heights 1 h and 11;, of the individual sections.

CUP/IPRESSION AND EXFANSION TVIACWE FOR'GASEUUS BOBIES Karl Bechtold, Anmuhle Hamburg,

Application February 28, 1956, Serial No. 568,391

Claims priority, application Germany March 3, 1955 3 Claims. (Cl. 23ll14t)) In order to cope with relatively great diiferences in pressure in the dynamically interesting conditions of gases and steam, in practice piston engines are mainly used for compression and expansion. So-called rotary engines (rotary piston, drum, axial, worm, chamber piston engines etc.) in general, and special constructions thereof in which, for instance, the drum rotates with the piston in the same direction, and in which liquid rings rotating with the drum are used as pacl ings, are of importance only as blowers or Compressors to overcome relatively small differences in pressure.

The subject of the invention is a rotary engine with characteristic properties or" the piston engine, possessing production and working advantages, such as setup of the machine for any desired deliveries and pressure stages by selective coupling together of standard construction parts, freedom of the conveyed medium from oil, far-reaching realisation of the compressor isothermal lines for gases or carnotizatiou for steam, valveless construction without injurious spaces, complete mass equilibrium, low relative speeds between the sliding parts, working speeds of 3000 R. P. M. by direct coupled drive with the cheapest highspeed electromotors, and arrangement of compressor and driving motor or engine and current producer in one common housing.

in the drawing the subject of the invention is shown in one example of its construction.

Fig. la shows a longitudinal section through the machine;

Fig. 1b shows a cross section through the first piston section taken along line Il of Fig. la;

Fig. 1c is a vertical cross-sectional view of the machine shown in Fig. la taken approximately along the line IIII of Fig. la;

Fig. 1d is a similar cross-sectional view taken approximately along the line Ill-Ill of Fig. la;

Fig. 12 is a further vertical cross-sectional View of the machine of the invention taken approximately along the line IV--IV of Fig. la;

Fig. 2 shows a development of the piston surface;

Fig. 3 shows schematically the arrangement of the compressor within a refrigerator plant.

First of all the kinematic system on which the machine is based is described as follows:

According to Fig. 1a a cylindrical main rotatable piston of diameter [1, divided into separate sections K K and K by cylindrical partition plates T T T 3 and T with the diiferent axial spacings I1 I1 and 11 and is disposed in a rotatable and sectionally divided drum 2 having a bore D. The number of revolutions of piston and drum in the same direction is designated by n. The piston is connected to the hollow shaft 3 which is supported in a bushing 4, whereas the hollow shaft 5, which is supported in a bushing 6, bears the drum 2.

Piston 1 runs in drum 2 with an eccentricity e, so that D-a' is equal to 2e; thus the two parts touch each other along a generatrix of the piston and of the bore of the drum. Each piston section K K and K carries in These shdes S S and S are pressed against the inner surface of the drum under the influence of the centrifugal force of the rotating system and thus seal off from each other the crescent-shaped chambers between piston and drum. (Figs. lble.) For the partition plates T T T and T4 annular grooves N N N and N are provided in the drum, in which they too run eccentrically in such manner that the plates themselves always dip into the grooves with the minimum distance f. For-the mutual sealing of the chambers in an axial direction by means of the partition plates T T T and T in the grooves N N N and N a certain amount of sealing fluid is introduced into the rotating system, preferably quicksilver, which owing to centrifugal force fills up the grooves.

The partition plates T T T and T are each provided with pairs of recesses A A A and A (Figs. lb-le, Fig. 2) the position of which relative to the slides S S and S is shown in Figs. lb to le, the recesses of each pair being on diametrically opposite sides of piston 1 and the pairs of recesses being circumferentially spaced in relation to one another.

The subdividing of the piston by partition plates and slides is shown in the schematic development of the piston surface in Fig. 2. The gas sucked in by way of the hollow shaft 3 passes in the direction denoted by the arrow through the distributor head 7 of that shaft into the suction chamber 8. That suction chamber is sealed against the machine casing space 9 by the dividing plate T,,, which runs in the drum groove N and has no recesses. From the suction chamber the gas passes through the two recesses A in partition plate T one after another and into the two crescent-shaped chambers around section K during one revolution of the piston and is then during that same revolution discharged through recesses A in partition plate T into the space around section K By being forced into chambers that get smaller and smaller at each stage the volume of gas is compressed. In Fig. 2 the circumstances of compression and passage over the individual sections of the piston become evident if the tangent B-B between drum and piston is displaced in the direction R shown by the arrow over the piston development. The two gas paths (G, G) correspond with the two recesses in the dividing plates. To carry off the heat of compression a cooled oil circulation system 11 is provided for the surface cooling of the drum, which can at the same time be used for the forced lubrication of the bearings. An oil pump 12 sucks the oil out of the casing 9 and conveys it through an oil cooler 13 over the oil piping ll to the spray nozzles 14, which spray it constantly over the warm part of the drum. The rotor 15 of an electrornotor also housed in the casing 9 is mounted directly on the hollow shaft 3 of the piston l.

Sealing'of the hollow shaft 3 against the casing 9 and the suction connection 16 is effected by a slip-ring packing 17. The hollow shaft 5, on which the drum 2 is mounted, is also sealed against the pressure connection 18 by means of a slip-ring packing l9. The transmission of the piston rotation to the drum in the same direction is effected by well-known means, e. g., over double-trunnioned guide cranks Zll.

To prevent the spray oil from penetrating into the suction chamber over the arrester in N a slip-ring 21 is interposed between drum 2 and dividing plate T which, resiliently urged out of its groove, is pressed against T Fig. 3 shows schematically the arrangement of the aforesaid compressor within a refrigerator plant. The vapor of the cooling medium is sucked off from the evaporator 22 over a pressure-reducing valve 23, which keeps the suction pressure for which the compressor is intended at the proper value. The compression is efiected as described above, but it passes through an auxiliary injection of liquid cooling medium in one or several compression chambers in thegdry saturated area (carnotization). Into the inner cavity 24- of the piston there opens a fixed pipe 25 that passes through the hollow shaft 5. Through this pipe, and through an auxiliary injection valve 26 liquid from the condenser 32 is sprayed into 24, which, driven by centrifugal force, passes throughthe bores 27 and through calibratednozzles 23 into the desired compression chamber (drawn only for one chamber). By evaporation of this injected liquid the gas content of the chamber is cooled and thus passes from the overheated state to the dry saturated condition.

For the recovery of any sealing fluid, e. g., quicksilver, that may have been carried over, it is led out of a collecting pan 29 on the lower part of the condenser through a float valve 39 and the tube 25 into the chamber 24, bypassing the auxiliary injection valve 26.

The returning of the quicksilver is independent of the auxiliary injection and can be arranged separately, whereby it can then be led directly into the end of the compressor chamber-10. In order to bring back to the machine any quicksilver condensate that has been deposited in the pressure pipeline, a sleeve 31 is drawn from the pressure connection over the slip-ring packing l9 and the bore of the hollow shaft .5 is comically shaped in order to centrifuge the. quicksilverto the end of the compression chamber.

After auxiliary starting in the manner known for similar systems the compression machine described is suitable also for use as an expansion machinetsteam engine) if the direction of flow of the gas or steam is reversed.

What I claim is:

1. A rotating compression and expansion machine comprising a rotatable piston disposed eccentrically in a rotatable drum for simultaneous 'uniformrotation therewith, said piston being provided. with radially movable slides engaging the internal surface of said drum, a plurality of separation plates of different axial spacings secured to said piston and subdividing the space between the external surface of said piston and theinternal surface of said drum in the axial direction into a plurality of axiallyaligned. chambers of crescent-shaped cross-section, said plates being provided with pairs of radial slots communicating with said chambers and said drum being provided with radial grooves for receiving the peripheral portions of said plates, said radial grooves being filled with a sealing fluid in which said peripheral portions are immersed upon rotation of said drum, the slots in the separation' plates interconnecting the axially-aligned chambers and being relatively circumferentially ofiset so that gaseous fluid drawn into the chamber atone end of said drum.

is caused to pass seriatim in a sinuous path through said axially-aligned chambers.

2. A rotating compression and expansion machine comprising a rotatable piston disposed eccentrically in a rotatable drum for simultaneous uniform rotation therewith, said piston being provided with radially movable slides A engaging the internal surface of said drum, a plurality of separation plates of different axial spacings secured to said piston and subdividing the space between the external surface of said piston and the internal surface of said drum in the am'al direction into a plurality of axiallyaligned chambers of crescent-shaped cross-section, said plates being provided with pairs of radial slots communicating with said'chambers and said drum beingprovided with radial grooves for receiving the peripheral portions of said plates, said radial grooves being filled with a sealing fluid in which said peripheral portions are immersed upon rotation of said drum, the slots in the separation plates interconnecting the axially-aligned chambers and being relatively circumferentially. ofis'et so that gaseous fluid drawn into the chamber at one end of said I drum is caused to pass seriatim in a sinuous path through said axially-aligned chambers, said drum being rotatably mounted in a housing and said piston having a shaft extending from said drum through said housing, and seal means to'prevent escape of fluid into said housing from said drum, said seal means comprising a radial sealing plate secured to said piston shaft'and an annular packing carried by said drum around said piston shaft, said drum being formed with a radial groove receiving the peripheral portion of said sealing plate.

3. A rotating compression and expansion machine comprising a rotatable piston disposed eccentrically in a.

rotatable drum for simultaneous uniform rotationtherewith, said piston being provided with radially movable slides engaging the internal surface .of said drum, a plurality of separationplates of different axial spacings secured to said piston and subdividing the space between the external surface of said piston rod and the internal surface of said drum in the axial direction into a plurality of axially-aligned chambers of crescent-shaped cross-section, said plates being provided with pairs of radial slots communicating withsaid chambers andsaid drum being provided with radial grooves for receiving the peripheral portions of, said plates, said radial grooves being filled,

with a sealing fluid in which said peripheral portions are immersed upon rotation of ,said drum, the slots in the separation plates interconnecting the axially-aligned chambers and being relativelycircumferentially oflfset so that gaseous fluid drawn into the chamber at one end of said drum is caused to pass seriatim in a sinuous path through said axially-aligned chambers, condenser means communicating with the interior of said drum for receiving the effluent from said drum and condensing any sealing fluid carried along by the efliuent, and means for returning said sealing fluid to the. interior of said drum.

References Cited in the file of this patent UNITED STATES'PATENTS 

